Variable capacity reciprocating pump



Jan. 18, 1966 J, N. WlLLlAMS VARIABLE CAPACITY RECIPROCATING PUMP Filed Jan. 27, 1964 INVENTOR. JOHN N. WILLIAMS United States Patent 3,229,640 VARIABLE CAPACITY RECIPROCA'IING PUMP John N. Williams, 4172 The Hill Road, Bonita, Calif. Filed Jan. 27, 1964, Ser. No. 340,164 4 Claims. (Cl. 103-37) This invention relates generally to pumps and more particularly to a variable-capacity reciprocating pump in which means are provided to adjust the cylinder relative to the piston to vary the volume of fluid discharged on each stroke of the piston.

It is, therefore, the principal object of this invention to provide a variable-capacity reciprocating pump having improved means to vary the effective stroke of the piston.

It is a further object of this invention to provide a variable-capacity reciprocating pump having improved means for varying the effective stroke of the piston while the pump is in operation.

It is a further object of this invention to provide an improved variable-capacity reciprocating pump which utilizes a by-pass port between the cylinder and inlet side of the pump to determine the effective capacity of the pump.

Finally, it is an object to provide a variable-capacity reciprocating pump of the aforementioned character which is simple and convenient to use and which will give generally efiicient and durable service.

With these and other objects definitely in view, this invention consists in the novel construction, combination and arrangement of elements and portions, as will be hereinafter fully described in the specification, particularly pointed out in the claims, and illustrated in the drawing which forms a material part of this disclosure and in which:

FIGURE 1 is a side elevation view of the invention and FIGURES 2, 3, 4 and 5 are longitudinal sectional views of the invention on an enlarged scale with the adjusting mechanism and piston in various operating positions.

Referring now particularly to FIGURE 1 of the drawing, it will be seen that this invention consists of an elongated base member having an upstanding abutment 11 on one end thereof. The base member is shown for purposes of illustration only as being horizontally disposed and it is to be understood that it may be oriented at any desired angle. Fixedly secured to the abutment 11 is a supporting cup 12 in the center of which is located a spherical recess receiving the ball end 13 of adjusting member 14. An internally threaded recess is provided in the end of adjusting member 14 opposite the ball end 13. Recess 15 receives an adjusting screw 16 that extends beyond the closed end 28 of cylinder 17.

A piston 18 having a head 29 is reciprocably mounted in cylinder 17. Any suitable means may be utilized for this purpose. As here shown piston 18 is connected to eccentric pin 20 on a flywheel or crank disc 19. The flywheel or crank disc 19 is rotated by shaft 21 mounted on support 22 and driven by any suitable source of power.

A horizontally disposed fluid supply and discharge conduit 23 which may be in the form of a flexible pipe, is mounted above the cylinder 17. As will be clearly seen in FIGURE 1 this conduit extends from a supply reservoir 31 to a discharge or outlet pipe 32. Two constantly open ports connect the supply conduit 23 with cylinder 17. A by-pass port 24 extends between conduit 23 and cylinder 17 intermediate the ends thereof. A combined inlet and outlet port 25 connects the cylinder with the conduit 23 adjacent the head 28 of cylinder 17. A check valve 26 is positioned in conduit 23 between ports 24 and 25 and is adapted to close upon increase of pressure in cylinder 17. A check valve 27 is positioned in conduit 23 between port 25 and discharge pipe 27 and is adapted to open as pressure is built up in cylinder 17.

In operation, the piston 18 is reciprocated with a fixed length of stroke under control of the flywheel or crank disc 19 and pin 20. With reference to FIGURE 2, piston 18 is shown at the end of the suction stroke with the cylinder full of the material to be pumped. Valve 27 will be closed while valve 26 will be open. On the pressure stroke material in the cylinder 17 will be returned to the reservoir 31 through by-pass port 24 until the piston has travelled to the left a sufficient distance to cover this port. Further movement of the piston will force the material out port 25. This material will be under a pressure head suflicient to open valve 27 and close valve 26 thereby forcing material into conduit 23 and outlet pipe 32.

FIGURE 3 shows the piston at the end of the pressure stroke. It will be readily apparent that the volume of the pump on this stroke is equal to the area of the piston multiplied by the effective stroke, which is the distance between the edge of the port 24 and the end 29 of the piston at the end of the pressure stroke. In this position the pump is operating at minimum capacity.

Turning now to FIGURES 4 and 5 it will be seen that the effective stroke of the piston has been changed by changing the position of the by-pass port 24 with respect to the end of the piston. This is accomplished by rotating the adjusting member 14 relative to the adjusting screw 16 to force the cylinder 17 to the right. At the beginning of the pressure stroke, FIGURE 4, the piston 18 is very close to the by-pass port 24 so that very little material will be returned to the reservoir 31 at the start of the pressure stroke. FIGURE 5 shows the piston at the end of the pressure stroke adjacent the head 28 of cylinder 17. It will be seen that the eifective stroke of the piston, and, therefore the capacity of the pump is much greater when in the position shown in FIGURE 5 than in the position shown in FIGURE 3. The capacity of the pump may be varied between the two positions shown by merely turning the adjusting member 14 the desired amount. This adjustment may be accomplished when the pump is operating as well as when it is idle.

It is to be understood that the improved pump herein described is not limited for use with liquids. It is suitable for use with gases or a slurry formed of a mixture of solids and liquid.

It is understood that minor variation from the form of the invention disclosed herein may be made without departure from the spirit and scope of the invention, and that the specification and drawings are to be considered as merely illustrative rather than limiting.

I claim:

1. A variable-capacity reciprocating pump comprising:

an elongated base member;

a fixed abutment on one end of said base member;

an adjusting member connected to said fixed abutment;

a cylinder having an open and a closed end;

means connecting said adjusting member and cylinder for relative longitudinal movement therebetween;

a piston having a head slidably mounted in said cylinder;

means on the other end of said base member to reciprocate said piston;

a supply and discharge conduit coextensive with said cylinder;

a combined inlet and outlet port adjacent the closed end of the cylinder connecting said cylinder with said conduit;

a by-pass port intermediate said closed and open end of said cylinder connecting said cylinder with said conduit;

3 4 a check valve positioned in said conduit on the outlet a combined inlet and outlet port adjacent the closed side of said combined inlet and outlet port; and end of said cylinder connecting the cylinder with said a check valve positioned in said conduit between said conduit;

combined inlet and outlet port and said by-pass port, a by-pass port intermediate said closed and open end of the capacity of said pump being adjustable by movesaid cylinder; ment of said cylindertrelative to said last mentioned 5 a check valve positioned in said conduit on the outlet means. side of said combined inlet and outlet port; and 2. The combination of claim 1 in which said supply a check valve positioned in said conduit between said and discharge conduit is flexible. combined inlet and outlet port and said by-pass port,

3. A variable-capacity reciprocating pump comprising; the capacity of said pump being adjustable by rotatanelongated base member; 10 ing the adjusting member relative to the stud to a fixed abutment including a spherical recess on one changethe distance between the closed end of the end of said base member; cylinder and the piston head, an internally threaded adjusting member having a 4. The structure of claim 3 in which said supply and spherical nose located in said spherical recess; 5 discharge conduit is flexible.

a cylinder having an open and a closed end; 1 1 a threaded stud extending from the closed end of said R feren es Cited by the Examiner cylinder and cooperating with said threaded recess; UNITED STATES PATENTS 15:12); having a head shdably mounted 1n said 2,821,926 2/1958 Miller 103-47 means on the other end of said base member to recip- 20 2,980,024 4/1961 Pope 103-37 mate sald PM); LAURENCE v. EFNER, Primary Examiner.

a supply and discharge conduit coextensive with said cylinder; 

1. A VARIABLE-CAPACITY RECIPROCATING PUMP COMPRISING: AN ELONGATED BASE MEMBER; A FIXED ABUTMENT ON ONE END OF SAID BASE MEMBER; AN ADJUSTING MEMBER CONNECTED TO SAID FIXED ABUTMENT; A CYLINDER HAVING AN OPEN AND A CLOSED END; MEANS CONNECTING SAID ADJUSTING MEMBER AND CYLINDER FOR RELATIVE LONGITUDINAL MOVEMENT THEREBETWEEN; A PISTON HAVING A HEAD SLIDABLY MOUNTED IN SAID CYLINDER; MEANS ON THE OTHER END OF SAID BASE MEMBER TO RECIPROCATE SAID PISTON; A SUPPLY AND DISCHARGE CONDUIT COEXTENSIVE WITH SAID CYLINDER; A COMBINED INLET AND OUTLET PORT ADJACENT THE CLOSED END OF THE CYLINDER OF CONNECTING SAID CYLINDER WITH SAID CONDUIT; A BY-PASS PORT INTERMEDIATE SAID CLOSED AND OPEN END OF SAID CYLINDER CONNECTING SAID CYLINDER WITH SAID CONDUIT; A CHECK VALVE POSITIONED IN SAID CONDUIT ON THE OUTLET SIDE OF SAID COMBINED INLET AND OUTLET PORT; AND A CHECK VALVE POSITIONED IN SAID CONDUIT BETWEEN SAID COMBINED INLET AND OUTLET PORT AND SAID BY-PASS PORT, THE CAPACITY OF SAID PUMP BEING ADJUSTABLE BY MOVEMENT OF SAID CYLINDER RELATIVE TO SAID LAST MENTIONED MEANS. 